Engine valve



Feb. 9, 1932. c, STEWART 1,844,021

ENGINE VALVE Filed June 15, 1929 Patented Feb; 9, 1932 f UNITED; STA E-sPATENT; OFFICE cARL n. srnwnm', on nnrnorr, MICHIGAN ENGINE VALVEApplication filed June 15, 1929. "Seria1 No. 371,249,

My inventionrelates to engine. valves, and 'moreparticularly to internalcombustion engine valves of the poppet type,

One *ob'ectof my present invention is to provide a valve actuatingstructure which may be automatically lubricated by conneca vention inseveral forms of embodiment, whlch are illustrated in the accompanylngdrawings, in which the same reference-characters indicate. like parts inthe several views, and wherein rFigure 1 is a vertical sectionofpart ofan internal combustion engine block provided with one form of valve andvalve-operating means constructed accordance with; the presentinvention;

.11 Fig. 2 is a perspective view of the form of push rod shown-in Fig.1;

Fig. 3 is a vertical section showing a modified form of valvestempand-In the .drawings, 1' designates generally" a fragmentary section of anengine block, provided with a valve seat 2, in-.which is fitted 1 apoppet valve3 having the. usual valve stem 1740 twhich reciprocates inthe valve stem -gu1de 5. A coil spring 6, surrounding the valve stem 4and compressed between one end of the guide 5 and a bearing 6', servesto maintain the valve normally seated. The valve 1s 1 $5315 opened atappropriate periods in the cyclic operation of the engine by means ofthe arrangement of cam, tappet and push rod which .will now bedescribed.

so The tappet 7, reciprocally mounted in they guide 8 at the lower partof the engine block 'ently be described. Y

the valve stem.

1, is provided with a cam follower shoe 9 which bears upon the usualengine-driven .cam (not shown) In a screw-threaded socket 10 at theupper part of the tapp'et 7 is received thethreaded shank 11 of a pushrod generally designated 12. The upper end of this push rod 12engage'sthe lower end of the valvestem 4', so that the push rod providesconnection between the tappet, and the "valve stem to transmit thereciprocating motion of the tappet to the valve stemand thusperiodically unseat the valve In each of the modifications of myinvention the engaging ends of valve stem and push rod arecomplementally 'configured'with conical sockets and 6 projections toeffect a maximum bearing surrace between the two members and to mduce atendency toward automatically maintaining the pushrodand the valve stemin coaxial alignment. The complemental conical surfaces also provide arelatively large area for the reception ofa lubricant,as will presn inFig 1 the ush, rod

1 In the form she 12 is comcally recessed at 13, and t e valve stem isconically extended at 14; while in l the modification illustrated byFig. 4 this arrangementis reversed, the push rod having a conicalextension 1362, and the -valve'stem beingprovided with a complementalconical recessl laf l t 1 7 It will be noted that in the forms of my t.,invention shown in Figs. l,. 2 and 4!, a spe- Fig. l is a vertlcalsectlonof; a further 2.2.1 modified form of valve-stem-and push rodwhich I have invented, I'may provide a de-i tachable-fitting having aconical projection 14?), as shown in'Fig, 3. A small set screw 14cserves to secure this fittingtothe end of.

. Y The apex angle Jofthe 'complemental con i cal surfacesemployedin myinvention may i be of approximately any magnitude between say 20 anddegrees. I 'have obtained best results, however, and therefore prefer to"use 0 conical surfaces having an apex angle of about 60 degrees.

In each form of my present invention the push rod 12 is made adjustableaxially of the tappet 7 through the medium of the polyhedral face 15formed on the push rod, and the lock nut 16Ien'gaged with the threadedshank 11 and adapted to bear against the upper end of the tappet 7 Bymeans of this arrangement of parts, ad-j-ustment may be made whenevernecessary, in an obvious manner.

To aid in silencing the operation of the parts hereinbefore described,and to pre vent undue wear, I have provided a lubricating system whichwill now be described.

An Oll passage 17 penetrates the lower part of the block 1 andcommunicates at its outer end through a coupling 18 with the customarypressure oil supply of the engine. At its inner end the passage 17communicates with a relatively narrow, vertical channel or slot 19formed in "the bore of the guide 8; and terminating in this channel 19is a spiral groove '20 also formed in the "bore of guide 8. The shank 11of the push rod 12 is formed of such length that whatever may be itsoperatively adjusted position in "the socket duct 23 axially of the pushrod 12 places the valve stem bearing surface of the latter incommunication with the'sump 21. In the form shown in Figs. 1, 2 and '3,where the push rod 12 is 'conically recessed, I have found it desirableto make the'u'pper end of the duct 23 slightly enlarged, as shown'at 2a,to provide a large amount of clearance for the apex "of the conical end14 of the valve stem ti, and in the modification 0f the inventionillustrated in Fig. 4, where the valve stem is conic'all-y recessed, asimilar cavity 24a is formed in the valve stem. for the same purpose. 7

It will beapparentthat during operatio of an engine provided with thedevice hereinbefore described, lubricating oil from the pressure supplywill be forced through the system formed by the passage 17, channel 19,

groove 21, horizontalduct22, sump 21and vertical duct 23, to lubricatethe contacting conical surfaces of the valve stem and push rod.Theconical configuration of these surfaces of the valve stem and pushrod provides a relatively large area for the .recep- .tionof thelubricant and resultsin a greater quantity of the lubricant beingmaintained between the contacting surfaces of these two members thanwould be possible if the valve stem and push rod were provided with theusual plane contacting faces. The film of oil thus kept between the twosurfaces has been found exceedingly effective in minimizing the soundordinarily caused by impact of the parts when not so lubricated. More--over, -some of the oil received by the channel 19 will travel down thespiral groove 20 to lubricate the reciprocating movement of the rta apet7 in its guide 8 and lessen the wear of these parts.

It will be apparent from the foregoing description and the accompanyingdrawings that I have provided means for conducting a lubricant from apressure supply to the contacting surfaces of tappet and guide, as wellas valve stem and push rod, with the inevitable loss of effective tappetguide bearing'surface reduced to a minimum.

it is to be understood that my present invention is capable ofexempliiication in other and further modifications not shown ordescribed in this application for Letters Patent, but all suchmodifications insofar as they embody the principles of the presentinvention are to ,be deemed within the scope and purview of the appendedclaims.

"What Iclaim-anddesire to secure by Letters Patent is:

-1. Thecombination of a-cam shafda valve stem, imeans interposedtherebetween for transmitting movement from the shaft to the valve,'said means *having complementary tazpered Einterfitting members andmeans for supplying fluid under pressure to the surfaces of saidta-pered members.

2. A tappet assembly comprising a base =memberadapted to be actuated bya cam, a second :member adapted to actuate a valve, said members havingcomplementary interfittingtapered portions, and means for supplying afluid under pressureto the sui faees ofsaid tapered portions. 7

3. A tappet assembly comprising a base member.adapted to beactuated by acam, said member having a tapered'opening therein, a second memberadaptedto actuate a valve, said second member having a tapered por-=tion fitting with said tapered opening Band means for supplying fluidunder pressure to 'the lowerend of said tapered opening forpassage'tothe surfaces of said tapered'por- 'tions.

In testimony whereof Iaflix my signature.

CA RL STEWART.

